CARACAS (Reuters) - Venezuela's top court on Friday ruled that President Nicolas Maduro is indeed Venezuelan, responding to years of opposition speculation that the socialist leader was in fact born in neighboring Colombia and has dual citizenship.

"The incontrovertible evidence demonstrates with absolute certainty that the aforementioned Venezuelan head of state was born in Caracas," said the Supreme Court ruling, which also assured Maduro has no other nationality.

The court did not say what evidence it reviewed.

Opposition leaders have demanded that Maduro show a birth certificate, and have noted discrepancies between different statements by public officials regarding where he was born.

Some have sought to remove him from office on the grounds that a second nationality would not allow him to hold the presidency. That effort has never advanced because opposition activists have been unable to obtain his birth certificate.

The issue surfaced this week during a largely symbolic political trial of Maduro being carried out by the opposition-led National Assembly, which has accused him of violating democratic principles.

"The president has been repeatedly asked to show his birth certificate to put an end to conjecture about his dual citizenship and until now he has not done so," said National Assembly President Henry Ramos on Thursday.

Maduro, who over 20 years rose from a bus driver and union leader to foreign minister and then president, dismisses such claims as a smear campaign against him.

(Reporting by Deisy Buitrago; Writing by Brian Ellsworth; Editing by Bernard Orr)